快猫短视频

FORGET the fancy chemicals. You can keep cells alive for days simply by
drying them and sticking them in a vacuum-sealed bag.

The discovery could slash the cost of cell implants designed to treat
diseases such as diabetes by making it easier and cheaper to store and ship
cells.

Until now, biologists thought that our cells didn鈥檛 have any way of
protecting themselves against drying out. Attempts to store tissues by freezing
or drying have focused on adding the protective chemicals some plants and
animals have evolved to protect their cells
(快猫短视频, 21 April, p 7).

Fred Levine鈥檚 team at the University of California, San Diego, was trying to
fine-tune a method of drying skin cells using the sugar trehalose, which
preserves structures within cells as water is lost. But some cells dried this
way still died.

The researchers suspected they were being killed by highly reactive chemicals
called free radicals, which are generated by cells processing oxygen. So they
tried vacuum sealing the dried cells in plastic bags. It helped鈥攂ut to
their surprise, some control cells that had been dried without trehalose also
survived. 鈥淲e put off publishing for a very long time,鈥� says Levine.

But repeated experiments have confirmed the findings. About a third of the
skin cells start growing again when rehydrated after three days at room
temperature. A tenth survive for five days, and a few can be revived even after
two weeks. 鈥淭he same is true for a variety of cells,鈥� says Levine. But without a
vacuum, all the cells die in three days.

鈥淚 would have expected to see dramatic damage to cells treated this way,鈥�
says Mehmet Toner, a tissue engineer at Harvard Medical School in Boston. 鈥淭his
really pushes the frontier forward.鈥�

Levine has already successfully used the technique to ship cells across the
US. But he suspects that some protectant will be needed if most cells are to
survive weeks or months rather than days.